A cyclo-P6 Ligand Complex for the Formation of Planar 2D Layers

The all‐phosphorus analogue of benzene, stabilized as middle deck in triple‐decker complexes, is a promising building block for the formation of graphene‐like sheet structures. The reaction of [(CpMo)2(μ,η6:η6‐P6)] (1) with CuX (X=Br, I) leads to self‐assembly into unprecedented 2D networks of [{(CpMo)2P6}(CuBr)4]n (2) and [{(CpMo)2P6}(CuI)2]n (3). X‐ray structural analyses show a unique deformation of the previously planar cyclo‐P6 ligand. This includes bending of one P atom in an envelope conformation as well as a bisallylic distortion. Despite this, 2 and 3 form planar layers. Both polymers were furthermore analyzed by 31P{1H} magic angle spinning (MAS) NMR spectroscopy, revealing signals corresponding to six non‐equivalent phosphorus sites. A peak assignment is achieved by 2D correlation spectra as well as by DFT chemical shift computations. The triple‐decker complex [(CpMo)2(μ,η6:η6‐P6)] forms with CuX (X=Br, I) novel two‐dimensional planar networks that resemble graphene‐like sheets. A unique distortion of the hexaphosphabenzene ligand occurs during this process. The polymers were characterized by X‐ray structural analysis, 1D and 2D 31P{1H} MAS NMR spectroscopy, and also DFT chemical shift computations.